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Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2025-2521

HIGH · 8.6 CVSS v3.1 Published 2025-07-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The Honeywell Experion PKS and OneWireless WDM contains a Memory Buffer vulnerability in the component Control Data Access (CDA). An attacker could potentially exploit this vulnerability, leading to an Overread Buffers, which could result in improper index validation against buffer borders leading to remote code execution. Honeywell recommends updating to the most recent version of Honeywell Experion PKS: 520.2 TCU9 HF1 and 530.1 TCU3 HF1 and OneWireless: 322.5 and 331.1. The affected Experion PKS products are C300 PCNT02, C300 PCNT05, FIM4, FIM8, UOC, CN100, HCA, C300PM, and C200E. The Experion PKS versions affected are from 520.1 through 520.2 TCU9 and from 530 through 530 TCU3.The OneWireless WDM affected versions are 322.1 through 322.4 and 330.1 through 330.3.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a memory buffer overread vulnerability in Honeywell Experion PKS and OneWireless WDM's Control Data Access (CDA) component. The vulnerability stems from improper index validation against buffer borders, allowing an attacker to read beyond buffer boundaries. Successful exploitation can lead to remote code execution on affected control system devices.

MitigationApply the vendor-supplied updates: upgrade Experion PKS to version 520.2 TCU9 HF1 or 530.1 TCU3 HF1, and OneWireless WDM to version 322.5 or 331.1. Test the updates in a staging environment before production deployment due to the critical nature of industrial control systems.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Honeywell products
    Review system inventory or use vendor tools to determine if Honeywell Experion PKS or OneWireless WDM is deployed in the environment
    Affected if Either Experion PKS or OneWireless WDM is installed
  2. Check Experion PKS version
    Access the Experion PKS system information panel or use the system's version lookup utility to determine the installed version (for example, look for version like 520.x or 530.x)
    Affected if The installed version is earlier than 520.2 TCU9 HF1 or 530.1 TCU3 HF1 (or the version cannot be confirmed as at or above these)
  3. Check OneWireless WDM version
    Access the OneWireless WDM administration console or system information to determine the installed version
    Affected if The installed version is earlier than 322.5 or 331.1 (or the version cannot be confirmed as at or above these)
  4. Verify CDA component is exposed
    Review network exposure and firewall rules for the Control Data Access (CDA) component port or service. Check if CDA is accessible from network segments outside the control system security zone
    Affected if The CDA component is network-accessible from less-trusted network segments or the internet

The environment is affected if either Experion PKS or OneWireless WDM is installed with a version lower than the fixed releases AND the CDA component is network-accessible.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor-supplied updates: upgrade Experion PKS to version 520.2 TCU9 HF1 or 530.1 TCU3 HF1, and OneWireless WDM to version 322.5 or 331.1. Test the updates in a staging environment before production deployment due to the critical nature of industrial control systems.

Recommended fix High confidence

Experion PKS: 520.2 TCU9 HF1 or 530.1 TCU3 HF1; OneWireless WDM: 322.5 or 331.1

  1. Identify the specific Honeywell product (Experion PKS or OneWireless WDM) and current version running in the environment
  2. For Experion PKS controllers (C300 PCNT02, C300 PCNT05, FIM4, FIM8, UOC, CN100, HCA, C300PM, C200E): If running version 520.1 through 520.2 TCU9, upgrade to version 520.2 TCU9 HF1
  3. For Experion PKS controllers: If running version 530 through 530 TCU3, upgrade to version 530.1 TCU3 HF1
  4. For OneWireless WDM: If running version 322.1 through 322.4, upgrade to version 322.5
  5. For OneWireless WDM: If running version 330.1 through 330.3, upgrade to version 331.1
  6. After upgrade, verify the CDA component version matches the patched release
  7. Test control system operations to ensure normal function after patching
Caveat Follow Honeywell's standard update procedures; coordinate with operations staff as control system updates may require planned downtime

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation6.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
30.0 hours of engineering $5,160
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-2521 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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